The development of a low-cost strong motion seismograph

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Date

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Thesis Discipline

Civil Engineering

Degree Grantor

University of Canterbury

Degree Level

Doctoral

Degree Name

Doctor of Philosophy

This thesis outlines the development of a universal network-based datalogger hardware system, seismic specific sensors and a suite of software to result in a low-cost accelerograph. The primary objective of the research has been to create a product that provides a service lifetime exceeding the ‘mean time before failure’ of the design's components while still maintaining low construction and maintenance costs. In place of the traditional approach of combining highly-integrated customised circuitry with a custom operating system, the accelerograph has been developed by focusing the design effort at a higher-level system of ‘off the shelf’ hardware modules which are connected by standard interfaces, with overall control and buffering of application-specific software provided by a generic operating system. The standard interfaces help ensure an ongoing range of compatible, equivalent (or improved) replacement modules, and the generic operating system ensures that they can be integrated quickly and easily with no modification to application-specific software. This buffering of the design from hardware changes increasing the product's tolerance to future module re-specification. The objective to achieve a low initial build cost necessitated the use of low-cost microelectromechanical (MEMS) silicon accelerometers. The non-ideal characteristics of these sensors resulted in the secondary objective of this research, to evaluate MEMS sensors for seismic monitoring purposes and to attempt to mitigate their non-ideal characteristics.